PC Thomas Perkins met the woman after she helped a vulnerable girl with mental health problems to get police help in September last year.
The officer took down her phone number during the incident, and six weeks later sent an unsolicited WhatsApp invite for a meeting in south London, which was near to his home.
“I thought you were very kind and generous with your support that day with the quiet one who needed help and would like to do something nice for you back”, he wrote.
“Can I invite you to (a part of London ) for lunch at a cute Bill’s and walk in the park.”
When the woman replied: “Sorry who are you?”, Perkins was undeterred.
“Oh dear I’m sorry”, he wrote. “It’s been too long maybe. At the beginning of September you helped a young girl who was unable to talk and I am the last copper who came (also with quite an abrupt female colleague, sorry about that!).
“I remember your kindness.”
Perkins was reported over the texts and hauled before a discplinary hearing, which this week concluded he should be sacked for gross misconduct.
Referencing Wayne Couzens, the Met Police officer who raped and murdered Sarah Everard after meeting her on duty, the panel said the woman contacted by Perkins had “felt very vulnerable”.
“This was to be expected and totally understandable. In the hinterland of the case of Couzens, any woman receiving an invitation to meet up from a male officer that she has come into contact with during a police investigation may be considered to be a vulnerable person.”
The panel dismissed Perkins’ claim that his actions only amounted to misconduct and he should avoid dismissal, criticising him for using personal details he had obtained through his policing work and making a disparaging comment about a colleague.
The panel found Perkins had tried to date the woman, at a location close to his home and on the weekend, and he had signed off the text “Tom” in an attempt to build an “emotional connection” with the woman.
“The murder of Sarah Everard has changed the landscape of how the police are regarded by the public, especially women”, added the panel.
“Any approach for an emotional engagement by an officer to a woman that they have met in the course of their duties may well understabably cause alarm and distress. It must never be done.
“PC Perkins brought discredit on the police force and undermined public confidence in it.”
He was sacked for gross misconduct and will be placed on to the list of disgraced former officers who are barred from policing indefinitely.
“We take every action necessary to maintain our professional standards and expect all staff to serve with professionalism, integrity, and compassion”, said Detective Superintendent Claire Cresswell, from the City of London Police Professional Standards Department.
“There is no place in the City of London Police for officers whose behaviour falls below the standards that we, as well as the public, expect.”